Altona refinery operations update

Update 23 November 2020

During November there may be an increase in flaring at Mobil Altona Refinery as we safely manage excess butane gas.  The butane gas is usually sent by pipeline to our nearby customer, Qenos, who will be undertaking essential maintenance during this period and have limited ability to take this gas while their manufacturing plants are shut down.

Butane is produced by all refineries as a product of the crude oil refining process.  At Altona Refinery, most of the butane produced is supplied to Qenos as a feedstock for plastics manufacturing, with the remainder used in gasoline blending to produce petrol.  Excess butane, beyond what can be blended into saleable product or sold as petrochemical feedstock, is used as fuel by the Refinery in place of purchased natural gas to meet Refinery’s energy needs.  Occasionally, additional excess butane must be safely burnt in the flare. 

The refinery has limited storage for liquefied gases, hence with the maintenance occurring at Qenos,  the refinery will have an excess of butane gas during November.

The EPA has granted Mobil a temporary approval to blend additional butane into gasoline to assist with managing the butane length during the Qenos Maintenance period in November.  However, there will still be some excess butane which the Refinery will need to manage. 

Flaring is the safest way for us to manage excess gases and is an important part of the refinery safety systems, however we realise that high levels of flaring can have an impact on the local community, so whilst there are a range of actions that we will take to minimise this impact as far as possible, there still may be a noticeable increase in the flare at times. 

We have developed a number of measures to reduce the impact of this flaring on our neighbours, particularly flaring of excess butane in night-time hours, including:

• Altering our process operations to reduce the need to flare,  by using as much of this excess butane in our own refinery fuel gas system as possible
• Altering our refinery process during periods of hot weather where recovery of gas in the refinery system can be difficult to achieve and result in higher ‘base’ flaring rates
• Closely monitoring gas production in the refinery to ensure this is minimised within the constraints of the production and gas recovery systems
• Managing site storage to allow for room to build butane stock in preference to flaring
• Working with Qenos to ensure maximised storage of butane during the time they are shut down for maintenance
• Continuously monitoring refinery noise levels using a noise meter and, where possible, adjusting our operations to address any issues identified
• Adjusting our flare steam rates to minimise smoke from the flare (as steam allows for a cleaner combustion of heavier gas material) and reduce any visual impact
• Ensuring that excessive steam is not used in the flare, as this can lead to increased noise levels
• Regularly monitoring the flare as part of routine field checks completed by Operators to ensure the flare and any noise impacts to the community are reduced as far as practicable.

To date, by ensuring the flare management plan as detailed above was enacted, flaring has been kept to a minimum throughout the first weeks of November and is expected to remain so for the remainder of the month.